One Field of Invention
Snubbers, or devices to arrest linear movement in one direction, have generally involved either hydraulic or pneumatic devices. These devices have included pistons and cylinders and variable pressure relief means. The hydraulic devices generally created leak problems in the packing glands and in the relief orifices. Pneumatic devices, not only have leak problems, but also their use was not practical where we had wide variations in temperature changes and moisture conditions. Also, pneumatic devices required considerable motion before any arresting action takes place, and, in general, were very bulky and thus their use was substantially limited.
The shortcomings of the hydraulic and pneumatic snubbers have resulted in the need of a mechanical snubber involving frictional contact between piston parts and a cylindrical bore controlling movement in one direction of travel and release of frictional contact between the parts during travel in the opposite direction.